// 参数加密算法 源于https://github.com/Binaryify/NeteaseCloudMusicApi
const crypto = require('crypto');
const iv = Buffer.from('0102030405060708');
const presetKey = Buffer.from('0CoJUm6Qyw8W8jud');
const linuxapiKey = Buffer.from('rFgB&h#%2?^eDg:Q');
const base62 = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
const publicKey = `-----BEGIN PUBLIC KEY-----\nMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDgtQn2JZ34ZC28NWYpAUd98iZ37BUrX/aKzmFbt7clFSs6sXqHauqKWqdtLkF2KexO40H1YTX8z2lSgBBOAxLsvaklV8k4cBFK9snQXE9/DDaFt6Rr7iVZMldczhC0JNgTz+SHXT6CBHuX3e9SdB1Ua44oncaTWz7OBGLbCiK45wIDAQAB\n-----END PUBLIC KEY-----`;

const aesEncrypt = (buffer, mode, key, iv) => {
    const cipher = crypto.createCipheriv('aes-128-' + mode, key, iv);
    return Buffer.concat([cipher.update(buffer), cipher.final()]);
};

const rsaEncrypt = (buffer, key) => {
    buffer = Buffer.concat([Buffer.alloc(128 - buffer.length), buffer]);
    return crypto.publicEncrypt({ key: key, padding: crypto.constants.RSA_NO_PADDING }, buffer);
};

const weapi = object => {
    const text = JSON.stringify(object);
    const secretKey = crypto.randomBytes(16).map(n => base62.charAt(n % 62).charCodeAt());
    return {
        params: aesEncrypt(
            Buffer.from(aesEncrypt(Buffer.from(text), 'cbc', presetKey, iv).toString('base64')),
            'cbc',
            secretKey,
            iv
        ).toString('base64'),
        encSecKey: rsaEncrypt(secretKey.reverse(), publicKey).toString('hex')
    };
};

const linuxapi = object => {
    const text = JSON.stringify(object);
    return {
        eparams: aesEncrypt(Buffer.from(text), 'ecb', linuxapiKey, '')
            .toString('hex')
            .toUpperCase()
    };
};

module.exports = { weapi, linuxapi };
